Electrolytic apparatus.



PATENTED JAN. 2, 1906.

H. S. BLAGKMORE. ELECTROLYTIC APPARATUS" APPLICATION FILED JULY 22.1903.

UNITED STATES PATENT OFFICE.

ELECTROLYTIC APPARATUS- Specification of Letters Patent.

Patented. Jan. 2, 1906.

Application filed July 22, 1903. Serial N0. 166,566-

fication.

cathode.

This apparatus is especially intended for the production of a lead-sodium alloy or a mercury-sodium amalgam and the recovery of the sodiumtherefrom as hydrate or oxid.

Referring to the accompanying drawings, Figure 1 is a transversevertical section of an apparatus employing a molten electrolyte and Fig.2 is a transverse vertical section of an apparatus employing an aqueoussolution of an electrolyte and a cathode of mercury, and Fig. 3 is atransverse vertical section of a modified apparatus.

The apparatus of Fig. 1 consists of the following parts: An iron vessel1 is set within a furnace-casing 2, of fire-brick, and supported thereinin part by an annular flange .3, ex'

tending outwardly from the upper edge of the vessel and resting upon thefire-brick, and in part by pier 4, rising centrally from the bottom ofthe furnace-chamber into supporting contact with the bottom of thevessel. The contents of the vessel are brought into a molten conditionby any suitable means, that shown, being a burner 5, extending throughan opening 6 in the side wall of the furnace. The electrolyte andcathode may be subsequently maintained in a molten condition by theelectrolyzing-current. From the flange of the vessel a cathode-terminal7 extends to a binding-post 8. The vessel has an iron'cover 9, supportedby but insulated from the vessel by an insulating-packing 10, preferablyof magnesia. The cover has a side opening 11, with closure 12, to permitthe introduction of lead, and a large central opening 13, within whichis arranged the anode-chamber 14. This anode-chamber consists of atubular casing 15, of iron, having an inwardly-extending flange 16 atits lower open end, a cover 17, with central opening for theanode-terminal, and a non-conducting lining 18, preferably of magnesia,which at the upper end of the chamber extends out between a flange atthe upper end of the casing and a corresponding flange on the cover'toprovide an insulating-packing. The anode-chamber has a lateral neck 19,with tight-fitting cover 20, for the introduction of sodium chlorid orother material to be eleotrolyzed. The flange 16 at the lower end of theanode-chamber supports a disk 21 of foraminous material, preferablyiron-wire gauze, which disk is overlaid by a diaphragm 22. Thisdiaphragm preferably consists of loose granular material of greaterspecific gravity than the molten electrolyte and less specific gravitythan the molten cathode arranged upon support 21 in a layer ofconsiderable depth. The material which I have found especially suitablefor such diaphragm when molten sodium chlorid is to be electrolyzed ismagnetite broken into angular fragments of such size as to pass througha'sieve having a mesh of fifty to the inch. The molten lead 23, actingas a cathode, preferably rises to such height in vessel 1 that theentire mass of loose material 22 constituting the diaphragm floats uponthe surface of the lead, the diaphragm thereby remaining in closecontact with the cathode notwithstanding considerable change in thesurface-level of the molten lead. The wire-gauze 21 is merelya safetydevice to prevent the material of the diaphragm from dropping out of theanode-chamber in case the molten lead falls to any abnormal low leveland is not necessary to the proper working of the apparatus. The anode24:, which may be a rod or rods of graphitized carbon, is carried by anadjustable rod 25, which may be of metal protected with porcelain andextends through a stufling-box 26 in cover 17. From one side of theanode-chamber extends an outlet-pipe 27 to draw ofl chlorin or othergaseous products, the removal of this chlorin being perfectly assistedby the action of an airinjeotor 28 in pipe 27, which serves to maintaina slight vacuum in the anode-chamber. The lead-sodium alloy produced byelectrolysis of the molten sodium chlorid being lighter than lead iscontinuously displaced as formed from the surface of the cathode beneaththe diaphragm and rises to the surface of the oathode around theanode-chamber, this being at a higher level than below the diaphragm.The alloy may be thence drawn off. It is preferable, however, tocontinuously remove the sodium from the alloy and convert it into itshydrate or oxid, the remaining lead being returned by gravity to thebottom of vessel 1 beneath the diaphragm to receive further additions ofsodium. This result may be accomplished invarious ways, but preferablyby the following means: WVithin and some distance below the surface ofthe molten lead cathode is an annular pipe 29, arranged around andconcentric with the anode-chamber. This pipe has two rows of downwardlyand outwardly opening perforations 30. Connecting with pipe 29 is a pipe31, having valve 32, which serves for the introduction of molten sodiumhydrate. This sodium hydrate, injected in a plurality of flue streamsinto the molten lead-sodium alloy, is reduced by the sodium to sodiumoxid with evolution of hydrogen, which rises and passes off from theelectrolytic cell through pipe 33. Sodium oxid rises and floats on thesurface of the cathode and, remaining in a molten condition, iscontinuously drawn off as it rises above a certain level by an invertedsiphon 34, extending from the side of vessel 1 and delivering into avessel 35, situated in an adjoining chamber in the brickwork of thefurnace. To facilitate the oxidation of the sodium, a layer of loosegranular conducting material is arranged at or near the surface of thecathode around the anode-chamber. This material may consist of smallangular fragments of iron, magnetite, of ferrosilicon. The materialshould be at least in part beneath the surface of the cathode, and thisarrangement may be effected either by employing a floating layer of suchdepth that its weight causes the lower particles to be submerged or byflxing a horizontal ring of wire-gauze between the anode-chamber 13 andthe outer wall of the vessel at or below the surface of the cathode.This loose granular. material serves to distribute the streams of sodiumhydrate rising from pipe 29 and bring them into thor-- ough and intimatecontact with the sodium in the alloy. The oxidizing reaction isfacilitated by the innumerable local couples due to the contact of thesodium and the relatively negative particles of iron, 82:0. The sharpcorners of the particles also increase the speed of the reaction. Theoxidation of the sodium may also be effected by successively introducingoxygen and hydrogen or air and natural gas through pipe 29, the oxygenserving to convert the lead-sodium alloy into sodium plumbate, which isthen reduced to metallic lead by the hydrogen with production of sodiumhydrate.

The sodium oxid received in vessel 35 is maintained in a moltencondition by any suit able means, as by the waste products escaping fromthe main furnace-chamber through a side passage 36, sweeping around thevessel and passing out through openings 37 in the supporting-flange ofthe vessel. Vessel 35 has a cover 36, through which passes the stem of afloat level-indicator 40. The sodium oxid may be withdrawn, if desired,through valved outlet 38. It is preferred, however, to continuouslyconvert this oxid into hydrate. For this purpose a pipe 41 leads up wardfrom beneath the level of the molten oxid in vessel 35 past asteam-injector 42, which serves both to introduce the water necessaryfor hydration and to carry the old material upward to a vessel 43. Theupper end of pipe 41 is bent and extends downward into vessel 43 to openbeneath the surface of the molten sodium hydrate therein. A springclosedair-inlet valve is arranged in the bend to prevent any siphoning ofhydrate back through pipe 41. Vessel 43 is heated by a burner 45 and hasa valved outlet 46 for the finished product. The cover of vessel 43 alsocarries a level-indicator 47. Such amount of sodium hyhrate as isrequired to oxidize the sodium taken up by the lead cathode continuouslypasses off from vessel 43 through a trapped outlet 48,communicating withpipe 31.

The modification shown in Fig. 2 is similar in most respects to theapparatus already described, with the exception that a mercury cathodeis employed, while the electrolyte is an aqueous solution, no externalheat being therefore required. The anode-chamber 14 is preferablyconstructed of glass or porcelain without lining. Theoxidation of thesodium taken up by the cathode 23 may be effected in the usual manner byplacing a layer of water 49 on the surface of the cathode around theanode-chamber, into which depend carbon electrodes 50, short-circuitedto the oathode by connections 51 to the metallic cover of the metalcontaining vessel. 1 preferably employ, however, for this purpose aperforated annulus of pipe 29 like that heretofore described, by whichwater or a dilute solution of sodium hydrate is injected into the bodyof the mercury sodium amalgam, the resulting strong sodium hydratesolution being withdrawn through side outlet 34. The resulting solutionmay be further strengthened by recirculating it through the amalgam,with or without previous additions of water. The floating diaphragm 22employed in this modification may be of broken magnetite, as heretofore,or of broken glass or silica sand. A layer 60 of conducting particles onand beneath the surface of the cathode around the anode-chamber may beemployed to facilitate oxidation of the sodium, as heretofore described.

l/Vhen sodium or other easily-oxidizable metal is deposited into themercury, the re sulting amalgam, being lighter than the mercury, risesaround the anode-chamber to a level Where the sodium is oxidized andremoved, the depleted mercury again returning to its position beneaththe diaphragm.

The term alloy as used in the claims is intended to also cover anamalgam or alloy containing mercury.

Various modifications may be made in the apparatus shown and describedwithin the scope of the generic claims. The partition which divides thecontaining vessel into an electrolyzing and an oxidizing compartment maybe of other form and arrangement than the tubular anode-chamber shown.The diaphragm and superposed electrolyte may be placed outside of thetubular partition and the oxidizing agent introduced within it, or astraight depending partition may be employed to partially separate thetwo chambers.

By the term depending partition as used in the claims is meant anypartition which has a passage or passages at its lower portion. If thediaphragm is a rigid sheet, both it and the partition may be arranged inan inclined position. In some cases the diaphragm may be entirelyomitted if care is taken to maintain the bodies of electrolyte, liquidmetal, and products of oxidation at uniform levels.

The height of the column of electrolyte required to counterbalance theliquid-metal cathode outside the anode-chamber may be decreased byslightly increasing the normal atmospheric pressure on the surface ofthe electrolyte. This may be easily effected by restricting the outflowof chlorin by regulatlug-valve or choking device 27 in the outletpipe 27and dispensing with the injector 28. The weight of this column restingon the oathode is advantageous, in that it serves to bring theelectrolyte and liquid metal into close contact.

The arrangement shown in Fig. 3 is similar to those already described,with the exception that the electrolyzing-current is passed in a reversedirectionthat is, from the liquid metal through the electrolyte. In thisfigure, 52 represents a vessel having a partition 53, both ofnon-conductive material, and a horizontal diaphragm 54:. The body 55, ofmolten lead, extends beneath the diaphragm and to a higher level at oneside of the partition. Electrolyte 56, fused sodium chlorid, floats uponthe lead and contains the cathode 59. Upon the other surface of themolten lead is a body of molten lead chlorid 57, communicating withwhich is the anode 58. The electrolytic current decomposes the sodiumchlorid, liberating the sodium, which may be skimmed off or, if thetemperature is sufliciently high, removed as a vapor. The chlorincombines with the lead, and the lead chlorid flows up into the body oflead chlorid, which is simultaneously electrolyzed, liberating chlorinand returning the lead to receive further addition of chlorin. Bydepressing the anode 58 into the lead lead may be continuously producedand drawn off, further additions of metallic lead being then required.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. An apparatus for electrolyzing lightmetal compounds, comprising anelectrolytic vessel having a means for producing a heavy and light metalalloy by the electrolysis of the light-metal compounds, in combinationwith means for displacing the heavy and light metal alloy by gravity,means for associating the heavy and light metal alloy with a metalhydroxid, means for removing the light-metal oxid thus produced, meansfor converting the light-metal oxid into light-metal hydroxid, and meansfor returning a portion of the lightmetal hyd roxid to the chambercontaining the heavy and light metal alloy.

2. An apparatus for electrolyzing lightmetal compounds, comprising anelectrolytic vessel ha ing a means for producing a lead and light-metalalloy by the electrolysis of the light-metal compounds, in' combinationwith .means for displacing the lead and light-metal alloy by gravity,means for associating the lead and light-metal alloy with a metalhydroxid, means for removing the light-metal oxid thus produced, meansfor converting the light-metal oxid into light-metal hydroxid,

ing light-metal oxid to the action of steam, .and means for returning aportion of the light-metal hydroxid thus produced to the chambercontaining the lead and light-metal alloy.

4:. An apparatus for electrolyzing alkalimetal compounds, comprising anelectrolytic 'vessel having means for producing a heavymetal andalkali-metal alloy by the electrolysis of the alkali-metal compound, incombination with means for displacing the heavymetal and alkali-metalalloy by gravity, means for associating the heavy-metal and alkalimetalalloy with a metal hydroxid, means for removing the alkali-metal oxidthus produced, means for converting the alkali-metal oxid intoalkali-metal hydroxid, and means for returninga portion of thealkalirmetal hydroxid to the chamber containing the heavy-metal andalkali-metal alloy.

5. An apparatus for electrolyzing alkalimetal compounds, comprising anelectrolytic vessel having means for producing lead and alkali-metalalloy by the electrolysis of the alkali-metal compound, in combinationwith means for displacing the lead and alkali-metal alloy by gravity,means for associating the lead and alkali-metal alloy with a metalhydroxid, means for removing the alkal-metal oxid thus produced, meansfor converting the alkali-metal oxid into alkali-metal hydroxid, andmeans for returning a portion of the alkali-metal hydroxid to thechamber containing the lead and alkali-metal alloy.

6. An apparatusior electrolyzing alkali- &

metal compounds, comprising an electrolytic metal hydroxid thus producedto the cham-.

ber containing the lead and alkali-metal alloy.

7. An apparatus for electrolyzing sodium compounds, comprising anelectrolytic vessel having means for producing a heavy-metal and sodiumalloy by the electrolysis of the sodium compound, in combination withmeans for displacing the heavy-metal and sodium alloy by gravity, meansfor associating the heavy-metal and sodium alloy with a metal hydroxid,means for removing the sodium oxid thus produced, means for convertingthe sodium oxid into sodiumhydroxid, and means for returning a portionof the sodium hydroxid to the chamber containing the heavy-metal andsodium alloy.

8. An apparatus for electrolyzing sodium compounds, comprising anelectrolytic vessel having means for producing lead and sodium alloy byelectrolysis of the sodium compound, in combination with means fordisplacing the lead and sodium alloy by gravity, means for associatingthe lead and sodium alloy with a metal hydroxid, means for removing thesodium oxid thus produced, means for converting the sodium oXid intosodium hydroxid, and means for returning a portion of the sodiumhydroxid to the chamber containing the lead and sodium alloy.

9. An apparatus for electrolyzing sodium compounds, comprising anelectrolytic vessel having means for producing lead and sodium alloy bythe electrolysis of the sodium compound, in combination with means fordisplacing the lead and sodium alloy by gravity, means for associatingthe lead and sodium alloy with a metal hydroxid, means for removing thesodium oxid thus produced, means for exposing the sodium oxid to theaction of steam, and means for returning a portion of v the sodiumhydroxid thus produced to the chamber containing the lead and sodiumalloy.

10. An apparatus for electrolyzing sodium chlorid, comprising anelectrolytic vessel having means for producing a heavy-metal and sodiumalloy by the electrolysis of sodium chlorid, in combination with meansfor displacing the heavy-metal and sodium alloy by gravity, means forassociating the heavy-metal and sodium alloy with a metal hydroxid,means for removing the sodium oxid thus produced, means for convertingthe sodium oxid into sodium hydroxid, and means for returning a portionof the sodium hydroxid to the chamblclr containing the heavy-metal andsodium a 0y.

11. An apparatus for electrolyzing sodium chlorid, comprising anelectrolytic vessel having means for producing lead-sodium alloy by theelectrolysis of sodium chlorid, in combination with means for displacingthe lead-sodium alloy by gravity, means for associating the lead-sodiumalloy with a metal hydroxid, means for removing the sodium oxid thusproduced, means for converting the sodium oxid into sodium hydroxid, andmeans for returning a portion of the sodium hydroxid to the chambercontaining the lead and sodium alloy.

12. An apparatus for electrolyzing sodium chlorid, comprising anelectrolytic vessel having means for producing lead-sodium alloy by theelectrolysis of sodium chlorid, in combination with means for displacingthe lead-sodium alloy by gravity, means for associating the lead-sodiumalloy with a metal hydroxid, means for removing the sodium oxid thusproduced, means for exposing the sodium oxid to the action of steam, andmeans for returning a portion of the sodium hydroxid thus produced tothe chamber containing the lead and sodium alloy.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

HENRY SPENCER BLACKMORE.

Witnesses:

(J. O. WRIGHT, H. N. JENKINS.

